The present invention relates to a process for laminating two or more transparent or translucent substrates or one transparent or translucent and one opaque substrate together. More particularly, the present invention relates to a process for laminating transparent or translucent substrates together using an adhesive which comprises a free radical addition polymerizable composition containing a photobleachable dye-counter ion complex such as a photobleachable cationic dye-borate anion complex or a photobleachable anionic dye-iodonium ion complex as a photoinitiator.
Current photo lamination techniques for glass and similar substrates involve bonding thin translucent layers together with a thermally cured adhesive. Photocrosslinkable and photopolymerizable adhesives have not been used extensively because the adhesives which have been available commercially employ UV initiators. Glass and plastic substrates tend to absorb heavily in the UV range making it impractical to use most UV sensitive adhesives.